As you may know, I’ve have been porting the MATE desktop, specifically MATE panel, to Wayland. The idea is that we’ll get all the shell components (panel, notifications, etc) and applications (Caja, Pluma, etc) Wayland compatible, then offer a “MATE on Wayland” session, with Marco and the X server replaced by a Mir-based compositor.

At the beginning, I determined the most complex piece would be MATE panel, and that’s why I’m happy to say that I’ve gotten it running inside Mir (video).

I’m currently working with the MATE developers to track down bugs and get initial Wayland support landed in master. Meanwhile, I’m also completing and improving Mir’s layer shell support, which is required for non-window surfaces (like panels and notifications). The changes to Mir will require an API break, so we’re holding off merging them until we’re sure we’ve gotten everything right.

When I read the Gnome-Shell 4 proposals on here https://wiki.gnome.org/Initiatives/Wayland/GnomeShell/GnomeShell4 I always wonder if just some compositor functionality could be moved from mutter to MIR to have MIR act as a proxy display server. That could spare the developers at least months or realistically rather years and years of rewrites.

Most of the ideas in there are indeed compatible with what Mir is and its long-term goals. We intend for Mir to be flexible enough to accommodate all the desktop environments out there while ensuring consistency in the mundane window management paradigms.